Electrically-heated syringe.



M. 1 1. SHOBNBEBG. LEGTBIGLLY HBATED SYRINGB APPLICATION FILED IAB. 6. 1912. 1,026,61 1'.

Patented May 14, 1912.

@X3i/immow- 4 QMH ' UNITED STATES PATENT OFFICE.

`I'IILTON H. SHOENBERG, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR '.ll'O -THE PRESTO ELECTRICAL MANUFACTURING COMPAJNY,

CORPORATION F CALIFORNIA.

0F SAN FRANCISCO, CALIFORNIA, A

ELECTRICALLY-HEATED SYRINGE.

Specication of Letters Patent.

Patented May 14, 1912.

' To all whom it may concern Be it known that I, MILTON H. SHOENBERG, a -citizen of the United States, residing at San Francisco, in the county of San Francisco and State of California, have invented new and useful Improvements in Electrically-Heated Syringes, of which the following is a specification.

My invention relates to hot-air syringes in which the air tlowing through the discharge nozzle passesv over an electrically heated'coil, and is especially adapted for use by dentists and surgeons. In instruments of this type, it is desirable that the heated air should be of a uniform temperature and also that the heating element should be under the direct control of the operator. It is also desirable that the heat should be concentrated near the nozzle in order that the heat-ing effect may be felt immediately and that the other portions of the instrument which arev liable to contact with the face orvbody of the patient may not become hot. l

It is the. purpose of my invention to embody the advantageous features above mentioned, and to-provide a syringe which will remain in 'a predetermined position in the hand of the operator when the bulb is manipulated,`and will not be liable to shift from one. side to the othen. I also provide.

means for avoiding any sparks'at the electrical contacts, so that the instrument may be connected to the ordinary lighting circuits.

Other objects will be manifest from the following description, in connection with the accompanying drawings, in Which--v Figure 1 is a side elevation of an instrument embodying my invention; Fig. 2v isa longitudinal section thereof; Fig. 3, is an enlarged detail viewl of the spring Contact arm; and Fig. 4 is an enlarged detail view of the electric heater. l

The nozzle tube 2,' carrying the nozzle 3, andthe brass or 'other metal current-carrying stem 5 are secured rigidly together by a hard-rubber or other insulating bushing 6, the tube 2 being preferably connected by means of a nut 7. A hard-rubber or other insulating bushing 9, is -fastened to me outer end of the stem 5, by means of an inner threaded metal ring 10, to which one of the electric conductors 12 is secured. v.The other conductor 14, passes through an aperture in the end of the bushing and is fastened under the ,head of a. screw 15, to which one yend of the insulated conductor 16, leading to the heater 18, is secured., the return heater conductor 19 being soldered or otherwise connected at 20 to the metal stem 5, thus forming a complete circuitvthrough the heater when the plug 22 is inserted in a socket of the electric lighting system or other source of electricit The electric heater is placed in the end of the nozzle tube, adjacent the nozzle 3. so-

that the effect of the heated coil will be felt at once upon the air discharged' through the nozzle. I construct-the heater of a continuous, tine resistance wire coil which is doubled upon itself, the two sections being separated by means of a mica or other insulating septun1323. which may be secured by means of' a binding cord 24.-. The mica separating member notI only serves to insulate the two parts of Ythe heater coil, but also serves as a heat-insulating support to maintain the heater at an intermediate point between the walls lof the nozzle-tube and prewhich is quite important.

I preferably make the heater coil of comaratively low resistance', and connect an incandescent lamp in series therewith when operating uponv av lighting circuit. There is,

-vent the possibility of contact therewith,

therefore, no danger of the heating coil being burned out.l` If the circuit is broken in a .clrcuithaving as hlgh a voltage as y1s found upon a lighting circuit, destructlve sparking occurs which will rapidly destroy For the. purpose of' soldered or otherwise fastened to the inner wall of the tube o at 26, and carrying a.

hard-rubber or other press-button 28-at its 100 free end, the shank of the button. passing through an aperture in the bushing.. Fastened to the spring-arm 9.5, by means of a bmding-cord 29, or otherwise, but insulated.

5 therefrom bya mica or other strip '30, is 'a metal strip '32, which is connected at one end by means oaiiexible wire 3a to the conductor 16, and'at the other end is adaptedfto be normally held in Contact with the l end of. the tube 5 at 35. It will thus be observed that normally vthe metal strip 32 forms a short-circuit `between Leonductor, 16 and the current-carrying stem' 5, thus shunting the current away from the heater-coil i 18. 'Bydepressing the press-button 28 with the linger, the Contact at 35 will be broken, andA the current will how through the vheater by' way/of ythe conductors 16, 19, 'andy the stem 5. Inasmuch'a's the current is not '20-interrupted.. when the contact strip 32 is :depressed by the button 9.8, but is merely :shifted through another path in the instruf ment,.there can he no sparking aty the contact 35x It will. be observed that the path l5 et' thefcili'rent 'through the-switch is entirely .by way of thecontact strip 32, and" not through the spring. Vfhen the instrument is eonnectedto a -low voltage battery., -so that the'sparlin'g upon the breaking of btheeircnit is ofno consequence, prefer to arrange the switch in series with the circuit, instea' of in shunt as just desribed. I As t have previously pointed out', it is importanh thatthe nozzle should remain 355 steadily in one position in the hand of'the operator whenit is'being manipulated so, that he may accurately direct the discharge of the air ciurent, When the -rnbbentbulb `V'fis attached tofthe end of the stein,fas -is 40? usual, the nozzle stem. isb shifted laterally withievery movement ot the bulb in defla- '..tion or ination.l Forthe purpose of obviating this defect, l pass the stem 5 entirely through the rubberbulb li-O, one

end:y bearing against the end of `the intermediate bushing i6," andthe other'end being pressed firmly by the outer bushing 9 whichV is screwed against it. AEach end of the bulb is thus positively supported and held bythe stem which serves as r`the central axis and prevents the bulb from shifting to one side when it is being deflatedA and .maintains the instrument in the same position. in the hand of 4the operator. rihebulb may be provided with an inlet valve 42, and the air is forced through the opening i3 into the hollow stem from whence it passes' into the nozzle tube. By means of the iinger button 28, the operator may instantly.

' control the air passing through they instruv ment, making it either warm-'or cool at will.

Ihave described iii-detail the ,construc- .tion illustrated inthe accompanying drawings for the purpose of disclosing an ein Londen bodiment of my invention, but l am aware that changes lmay be made therein, without' departing 'from the 'spirit of my invention,

and l aim to cover. snclimoditications inthe element in said tube comprising a spiral' resistance wire doubled upon itself andan insulating septum interposed between the portions of said spiral wire and separating thelieaterr'from the opposite walls of the tube. 7

2. An electrically heated syringe, comprising a nozzle tube, ay hollow stem, an insulating .bushing intermediate said-tube and stem, an elastic bulby surrounding said stem', abushing ,threaded to the other end of said stem and provided with electrical contacts', an electric heating coil in said tube, vand conductorsconnecting said coil and said contacts.

drin electrically heated. syringe, comprising' a nozzle tube, a hollow stem, an 'insulating bushing intermediate said tube and stem, an elastic bulb surrounding said stem, a bushing threaded to the other end of said stem and provided with electrical contacts, an electric heating coil in said' tube, conductors connecting said coil-.and

said'contacts, and a switch member Within said stem having al push-button projecting through an aperture in said intermediate bushing, said switch member being arranged to interrupt the iiow oeurrent from said conductdrs to'said heating coil.

f' An. electrically heated syringe, comlioo pri/sing a nozzle tube, a hollow metal stem provided .with a lateral'aperture, an insulating bushing connecting said tube and said stero, an elastic bulb surrounding. said stem, a bushing threaded to vthe outer end of said stem, an electric heating coil in said tube, conductors. passing through said end bushing, means connecting one of said conductors to said stem, a wire connecting the other conductor with one terminal of said coil, and a wire connecting the other end-oi' said coil with said stem.

5. An electrically heated syringe, comprising a nozzle tube, 'a hollow metal stem provided: with* a lateral aperture, an insulating bushing connecting said vtube and said stem, an elastic bulb surrounding said stem, a ,bushing threaded to the outer end .of said stem, an electric heating coil in said tube, conductors passing ythrough said end bushing, means connecting one of said conductors to said stem, a wire connecting the other conductor with one -terminal of said coil, a wire vconnecting the other. end oi said coilwith said stem, vand a spring-pressed switchmember withinlsaid stem having a my hand in presence of two 'subscribing Bush-button projecting through an aperture witnesses.

-m said4 intermediate bushinv' said switch y member being arranged to nirmally inter- MILTON H' DHOEB BERG' 5 rupt `the How offcurrent from saidl con- Witnesses:

ductbrs to .said heating coil. Llswls Annnsvonrn,

AIn testimony whereof Ihave hereunto set'.V M, Mmmm. 

